package com.example.newspublish.aspect;


import com.example.newspublish.annotation.AutoFill;
import com.example.newspublish.util.BaseContext;
import com.example.newspublish.util.OperationType;
import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.stereotype.Component;

import java.lang.reflect.Method;
import java.sql.Timestamp;
import java.time.LocalDateTime;

/**
 * 自定义切面，实现公共字段自动填充处理逻辑
 */
@Aspect
@Component
@Slf4j
public class AutoFillAspect {

    public static final String SET_CREATE_TIME = "setCreateTime";
    public static final String SET_UPDATE_TIME = "setUpdateTime";

    /**
     * 指定切入点
     */
    @Pointcut("execution(* com.example.newspublish.mapper.*.*(..)) && @annotation(com.example.newspublish.annotation.AutoFill)")
    public void autoFillPointCut() {

    }

    /**
     * 在前置通知，在通知中进行公共字段的赋值
     * @param joinPoint
     */
    @Before("autoFillPointCut()")
    public void autoFill(JoinPoint joinPoint) {
        log.debug("开启公共字段填充...");

        //获取当前被拦截的方法上的数据库操作类型
        MethodSignature signature = (MethodSignature)joinPoint.getSignature();//方法签名对象
        AutoFill autoFill = signature.getMethod().getAnnotation(AutoFill.class);//获得方法上的注解对象
        OperationType operationType = autoFill.value();//获得数据操作类型

        //获取当前被拦截的方法的参数--实体对象
        Object[] args = joinPoint.getArgs();
        if(args == null || args.length == 0) {
            return;
        }

        Object entity = args[0];
        //准备赋值的对象
        Timestamp now = new Timestamp(System.currentTimeMillis());
        Long currentId = BaseContext.getCurrentId();

        //根据当前不同的操作类型，为对应的属性通过反射来赋值
        if(operationType == OperationType.INSERT) {
            try {
                //为4个公共字段赋值
                Method setCreateTime = entity.getClass().getDeclaredMethod(SET_CREATE_TIME, Timestamp.class);

                //通过反射为对象属性赋值
                setCreateTime.invoke(entity, now);


            } catch (Exception e) {
                e.printStackTrace();
            }


        } else if(operationType == OperationType.UPDATE) {
            try {
                //为2个公共字段赋值
                Method setUpdateTime = entity.getClass().getDeclaredMethod(SET_UPDATE_TIME, Timestamp.class);

                setUpdateTime.invoke(entity, now);

            } catch (Exception e) {
                e.printStackTrace();
            }
        }


    }
}
